To measure the surface shape of a trove such as a clay pot, a person makes a sketch of it, measuring it with a ruler or the like, or a contact type measuring instrument which measures the surface shape of the object by tracing the contour of the object is used. A non-contact type measuring instrument which photographs the object using a slit light source or measures the object using a laser beam is also used.
In clothing stores, salespeople measure the body size of customers with tape measures to determine the size of clothing items which suit them best. In the case of a vehicle or a machine structure, a surface shape measuring apparatus is used to check a prototype in designing, to check the products before shipment, or to determine the replacement timing of parts at periodic inspections.
However, the equipment cost is high to measure the surface shape of a trove with a conventional contact or non-contact type measuring instrument. In the field of archeology, the surface state of a trove such as the patterns on its surface has to be plotted as images. However, it is difficult for the conventional system to plot the images precisely. More specifically, there are following problems, depending upon the way of measuring.    1) It takes significant time and effort for a person to measure the patterns and make a sketch of them. Although the work requires many skills, the results differ between individuals. Also, it is difficult to get high accuracy in dimension and shape.    2) In the case of a contact type measuring instrument, it takes long time to trace the surface of a trove as a measuring object. Also, after the measurement, an operator has to observe the characteristics on the surface of the trove and make a drawing of them.    3) With a non-contact type measuring instrument using a slit right or a laser beam, the surface of the trove can be measured in a non-contact manner. However, in plotting the surface shape or pattern, an operator has to plot it, comparing the real surface shape or pattern with the measurement data. Thus, the drawing is less accurate in the positional relation of the surface shape or pattern than the measurement data.    4) There is a problem common to the above cases 1) to 3). Since the drawing is made from an archeological point of view, the correctness of the drawing cannot be judged without comparing with a photograph of the object.    5) When a buried cultural property is found in a public work site, or civil engineering or construction work site, archeological survey is conducted. When the survey takes a long time, the interruption of the work is prolonged and the period of construction is prolonged. Thus, shortening of the archeological survey period is highly demanded by constructors. Speeding-up the plotting of buried cultural properties will significantly contribute to the public interest.
In the case of human bodies, there are many customers who don't want to have their body size measured by a salesperson. It may be a good idea to install a non-contact type measuring instrument for measuring the surface shape of a human body in retail shops. However, such a system has not been widely adopted since it causes a problem regarding privacy of the customers and requires the shops to invest a large amount of money.
In the case of a vehicle or machine structure, a large scale apparatus for measuring the surface shape is required and the measurement takes a long time. Especially, in checking products before shipment, a delay in the check affects the delivery date of the products to the customers. In periodic inspections, if the measurement cannot be quickly performed within a given period, the influence on the operation of the equipment will be significant at the customers.
In earth volume measurement, there are following problems.    1) It takes time and effort to smooth the earth. Also it is difficult to get high accuracy.    2) To measure the entire surface with a electro-optical distance measuring instrument or an ultrasonic distance measuring instrument is not practical because it takes a long time. Only a part of the earth surface is measured in some cases to shorten the measurement time, but it is difficult to get high accuracy.    3) When a GPS (Global Positioning System) is used, an operator must carry a GPS terminal. It is troublesome to the operator.
The first object of the present invention is to solve the above problems and to provide an apparatus and method with which the surface shape or pattern of a measuring object such as a trove or human body can be measured quickly. The second object of this invention is to provide a surface shape plotting apparatus which can make a precise drawing of the surface shape or pattern of a trove or the like measured with the surface shape measuring apparatus.